Substrates containing through substrate via (TSV), called TSV substrate herein, have been extensively used for packaging semiconductor chips or electric devices, which are the bridge connecting two or more electric devices with a fine pitch of electric contacts to a substrate or board with a coarse pitch of electric contacts in 3D and 2.5D semiconductor chip package. TSV substrates include silicon, glass, ceramic and organic TSV substrates. The methods of prior arts for making TSV substrates are generally fall into two categories: one is a substrate-based method (named herein), and the other is a via-based method (named herein). The substrate-based method basically comprises: 1) opening a patterned array of vias on a substrate (a piece of silicon, organic substrate or glass), and 2) using a conductive material to fill in the patterned array of vias. And the via-based method basically comprises: 1) forming a patterned array of vias on a carrier, 2) using a substrate material to cover and seal the patterned array of via, then polishing away the excessive substrate material above the patterned array of vias. An IC chip packaging substrate can be further produced by forming one or more layers of electric traces and pads on the upper and lower surfaces of the TSV substrate.
The substrate-based or via-based method of prior arts is called a micro method herein, wherein each via and its position are designed and made by using micro-level processing technologies. It is noted that the micro method for making TSV substrates has some limitations in its manufacture and application, including: 1) its manufacture is very time consuming and expensive, 2) the diameter of the via cannot be very small, for example, it is very difficult to make a via with diameter less than 10 um in a substrate thicker than 200 um, 3) the via pitch cannot be very small, for example, it is very difficult and expensive to make a via pitch less than 50 um in a substrate thicker than 200 um, 4) the thickness of TSV substrate is limited by the via diameter and pitch, wherein the smaller the via diameter and pitch is, the thinner the substrate has to be, 5) the very thin TSV substrates, usually being about 100 um in thickness, are easily broken in its further manufacture and application.
There are other types of methods of prior arts, called macro methods herein for making TSV substrates, wherein the TSV is not made through micro-level technologies such as etching or drilling each hole, but made from metal wires through macro-level technologies. As shown by the numerical symbol 40 in FIG. 1, the common part of the types of macro methods is to make a column of matrix containing a 3D array of parallel metal wires along the column direction, as shown by the numerical symbol 41, then saw the column of matrix into slices so as to produce TSV substrates, as shown by the numerical symbol 42; and the feature of each type of macro method is its way to make a column of matrix containing a 3D array of parallel metal wires. There are three types of macro methods of prior arts, as designated by the numerical symbol 10, 20 and 30 in FIG. 2. In the first method designated by the numerical symbol 10 in FIG. 2, a column of matrix containing a 3D array of parallel metal wires is made by rolling a coated metal wire 11 around a multiple side of column, then joining the coatings 12 together by using a designed temperature and pressure so as to form the column of matrix containing a 3D array of parallel metal wires on each side of the multiple side of column. In the second method designated by the numerical symbol 20 in FIG. 2, a column of matrix containing a 3D array of parallel metal wires is made by forming a matrix piece 22 with a plurality of parallel metal wires 21 first, then stacking a plurality of layers of such matrix pieces into a column of layered structure, and then joining the layers together into a solid entity by using a designed temperature and pressure so as to form a column of matrix containing a 3D array of parallel metal wires. Finally, in the third method designated by the numerical symbol 30 in FIG. 2, a column of matrix containing a 3D array of parallel metal wires is made by forming and fixing a 3D array of metal wires 31 in a framework as designated by the numerical symbols 33 and 34 first, then filling a filling material 32 into the empty space in and around the 3D array of metal wires 31, and then solidifying the filling material so as to form the column of matrix containing a 3D array of parallel metal wires.
In comparison with a micro method for making TSV substrates, the advantages of a macro method based on metal wires for making TSV substrates include: 1) TSV substrates can be produced cost-efficiently in batches, 2) the via diameter and pitch can be very small, 3) the thickness of the TSV substrates is not limited by the via diameter and pitch. It is noted that all the three types of macro methods are technologically feasible for making a plastic material of column containing a 3D array of parallel metal wires. Comparing the three macro methods as shown in FIG. 2, the first method is simplest, the third method can make a more complicated pattern of 3D array of parallel metal wires, and the second method is between them. However, when making a ceramic material of column of matrix containing a 3D array of parallel metal wires or ceramic TSV substrates, all the three types of macro methods technically have drawbacks. For the first two macro methods, aside from the high cost for making ceramic coating on a metal wire or thin ceramic pieces with metal wires, their drawback is that there are too many interfaces among ceramic coatings or ceramic matrix pieces. As a result, when joining the ceramic coatings or ceramic pieces together by using a temperature and pressure, it is difficult to ensure a good adhesion without voids among the coatings or without cracking or delaminating issue among the ceramic matrix pieces. As for the third type of macro method, because a filling material such as a paste type or powder type of ceramic material is used, it doesn't have the drawback due to the interfaces among ceramic coatings or ceramic matrix pieces as in the first and second types of macro methods. However, it has another drawback, that is, it is difficult to ensure that some of the thin and long metal wires are not moved away from their original positions or are not broken when filling a paste type or powder type of ceramic material among the metal wires because the metal wires are only fixed at their two ends by the framework. Summarily, in the first and second types of macro methods, the metal wires are well fixed, but the matrix material are the coatings or matrix pieces, causing the drawback that there are too many interfaces among coatings or matrix pieces, while in the third type of macro method, even though a filling material is preferably used, the metal wires are only fixed at their ends by the framework, causing the drawback that the metal wires are not well fixed and as a result, they can be moved or broken when applying the filling material.